BERLIN (Reuters) -- Germany's defense minister has tried to fend off attacks over his handling of a row about a German-ordered air strike in Afghanistan that killed civilians by saying opposition parties had the same information he had.

Karl-Theodor zu Guttenberg, who has rejected calls to resign, also confirmed reports the September 4 strike had targeted Taliban as well as two fuel tankers. Speculation about that has unleashed a fresh storm about the German troops' mandate.

"The Taliban were also a target of this bombardment -- the Taliban and the tankers -- and the opposition were informed of this," Guttenberg said at a party event in Munich today.

The 38-year-old, widely seen as a rising star among Chancellor Angela Merkel's conservatives, went on to turn the tables on his opponents who have accused him of lying.

"As far as the accusations of deception and lies in my period of office are concerned, I can only say that [SPD chief Sigmar] Gabriel and [Greens chief Juergen] Trittin must protect themselves from allegations of deception," he added.

A furor over new details of the strike, carried out by a U.S. warplane at the request of German ground forces, has created a big problem for Merkel as she weighs up whether to boost troop levels in Afghanistan.

Kabul says the attack killed 30 civilians and 69 Taliban.

The row has already claimed the job of cabinet minister Franz Josef Jung, defense minister at the time of the strike and the head of Germany's armed forces.

Guttenberg, who succeeded Jung as defense minister in October, has insisted he will keep his job. "I will stay, even if there is a storm going on around me," Guttenberg told RTL television late on December 13.

But his political opponents have seized on weekend media reports which said the strike was the result of an "escalation strategy" approved by the chancellor's office in the summer which allowed troops to remove leading Taliban members.

Some SPD and Green lawmakers say such tactics go against the parliamentary mandate under which German troops have been sent to Afghanistan, a charge the government rejected.

"The idea that the fundamental basis of the mandate has changed is wrong," said a government spokesman, responding to more than an hour of questions on the subject at a news conference.

Germany's foreign and defense policy is still affected by the legacy of the Nazi past and every deployment is subject to intense public scrutiny. Attacking other than in self-defence is a particularly sensitive subject.

A parliamentary committee starts an investigation of the strike on Wednesday and over coming months Guttenberg, and possibly even Merkel, will be grilled.

Opposition politicians want Merkel to make a statement to parliament to explain whether documents had been kept from her and whether the mandate for German troops had changed.

Germany has more than 4,000 soldiers in Afghanistan, making it the third largest contingent in the NATO-led force. They are mostly in northern areas and the government has refused to send them to the more dangerous south.